1. Field of the Invention
The present invention relates to a drug recognition device and a drug recognition method which recognize the type of drug having a stamped character thereon.
2. Description of the Related Art
In recent years, for example, when a doctor prescribes a plurality of types of drug which are taken at different times (for example, after breakfast, after lunch, and after dinner) for a patient in hospitals, unit-dose packaging which dispenses and packages a plurality of types of drug (for example, tablets or capsules) corresponding to one dose in one packet has been generally performed. Unit-dose packaging means that drugs corresponding to each dose which are picked by the pharmacist according to a prescription are set in a tray (also referred to as a tablet case) of a packaging machine and the packaging machine automatically packages the drugs in the tray in each packet. In the unit-dose packaging, in some cases, the pharmacist manually performs the picking of the drugs or the setting of the drugs in the tray. Therefore, the type of drug or the number of drugs which is different from that written in the prescription is likely to be erroneously packaged in a packet. For this reason, in order to determine whether the drugs packaged in a packet match those written in the prescription, the type of drug or the number of drugs is automatically recognized before or after the drugs are packaged in the packet.
For example, JP2012-165876A discloses an inspection device which captures the image of each packet of drugs set on a transparent plate, using cameras that are provided in a direction perpendicular to the transparent plate, and performs imaging processing for the captured images obtained by each camera to automatically recognize characters printed or stamped on the drugs. It is possible to recognize the type of drug on the basis of the result of recognizing the characters printed or stamped on the drug.
JP2013-148454A discloses a tablet inspection device which irradiates drugs packaged in a packet with parallel light and diffuse light at different times, captures the image of the drugs illuminated with each light component, generates a difference image between the image captured when the parallel light is emitted and the image captured when the diffuse light is emitted, and counts the number of drugs on the basis of the difference image.
JP2010-190786A discloses a print inspection device which illuminates a drug while switching the set amount (illumination conditions) of light from an illumination unit, captures the image of the drug whenever the illumination conditions are switched, and performs image processing (binarization process) for the image captured under each illumination condition to extract characters printed on the drug. Then, the print inspection device determines the optimum illumination condition in which the contrast between the printed characters and the background is the maximum among the illumination conditions and performs a process of capturing the image of the drug and image processing under the optimum illumination condition to recognize the characters (type name) printed on the drug.
JP2010-117331A discloses a granular article type inspection device which illuminates a drug in one illumination direction, using an illumination unit that can illuminate the drug in a plurality of illumination directions, captures the image of the drug to acquire a captured image, and performs image processing for the captured image to extract characters printed or stamped on the drug. Then, in a case in which the extraction of the printed characters or the stamped characters from the captured image has failed, the granular article type inspection device switches the illumination direction of the illumination unit, performs the imaging process and image processing again, and recognizes the characters printed or stamped on the drug.